银纳米粒子复合物在表面等离子体共振生物传感器中的应用研究

发布时间：2018-07-25 15:55

【摘要】：银纳米复合材料具有大比表面积、高电导率、良好的反应与催化活性,已被广泛用于新一代生物传感器的设计与制备过程。表面等离子体共振(Surface plasmon resonance,SPR)生物传感器是一种光学生物传感器,其测量原理为金属与电介质界面处产生的等离子体激元共振现象会受到界面处折射率的显著影响,而界面处折射率又与结合在金属表面的具体物质种类、形貌和质量相关。相比于其他常规生物传感技术(如荧光、同位素标记等),SPR生物传感技术无需标记,可简化实验操作并保证被测物质的生物活性。此外,SPR生物传感器可实时分析分子间的相互作用,能同时得到被测物的浓度和结合常数等信息。本文研究了银纳米粒子复合物在金膜表面的组装策略及其在表面等离子体共振生物传感器构建中的应用,主要研究内容包括:1.构建了一种基于银纳米立方体/壳聚糖复合物的新型SPR生物传感器,并将其用于检测鼠IgG。首先,通过硫化物介质方法制备出银纳米立方体(Ag NCs),利用透射电子显微镜和紫外可见吸收光谱法对其进行表征。然后,采用3-巯基丙酸修饰银纳米立方体,再将其与壳聚糖和戊二醛简单混合后,用旋涂法将所得复合物沉积到金膜上,并将抗体通过席夫碱反应固定到传感膜上。该新型SPR生物传感器的对鼠IgG信号响应浓度范围为0.60-40.00μg m L-1,与基于MPA修饰的传统SPR生物传感器相比检测下限降低了4倍。2.采用层层自组装技术构建了一种基于聚多巴胺-银纳米粒子-聚多巴胺-金(PDA-Ag NPs-PDA-Au)膜的新型SPR生物传感器,并将其用于检测马IgG。首先,在金膜上组装一层PDA膜,然后利用PDA原位还原Ag NO3形成银纳米粒子(Ag NPs),接着再组装一层PDA膜,最后通过席夫碱反应将抗体连接到PDA膜上。顶层的PDA膜还可有效地防止Ag NPs被氧化。实验中利用扫描电子显微镜和台阶仪(Talystep)对传感膜的形貌和厚度进行了表征。该新型SPR生物传感器对马IgG的检测下限为0.625μg m L-1,与基于PDA修饰金膜的生物传感器相比低2倍,与基于MPA修饰金膜的常规生物传感器相比低4倍。此外,该新型SPR生物传感器还具有较好稳定性和优秀的可再生性。
[Abstract]:Silver nanocomposites with large specific surface area, high conductivity, good reaction and catalytic activity have been widely used in the design and preparation of new generation biosensors. Surface plasmon resonance (Surface plasmon) biosensor is an optical biosensor whose principle is that the plasmon resonance at the interface between metal and dielectric will be significantly affected by the refractive index at the interface. The refractive index at the interface is related to the type, morphology and quality of the material bound to the metal surface. Compared with other conventional biosensor techniques (such as fluorescence, isotope labeling, etc.), SPR biosensor can simplify the experimental operation and ensure the biological activity of the substance. In addition, SPR biosensor can analyze the interaction between molecules in real time, and can get the information of the concentration and binding constant simultaneously. In this paper, the assembly strategy of silver nanoparticles on the surface of gold film and its application in the construction of surface plasmon resonance biosensor are studied. The main research contents include: 1. A novel SPR biosensor based on silver nanocube / chitosan complex was constructed and used to detect mouse IgG. Firstly, silver nanocrystalline (Ag NCs), was prepared by sulfide-medium method and characterized by transmission electron microscopy (TEM) and UV-Vis absorption spectroscopy. Then, the silver nano-cube was modified with 3-mercaptopropionic acid, then mixed with chitosan and glutaraldehyde, the complex was deposited onto the gold film by spin coating method, and the antibody was immobilized on the sensing film by Schiff base reaction. The response concentration range of the new SPR biosensor to rat IgG signal is 0.60-40.00 渭 g mL ~ (-1), which is four times lower than the traditional SPR biosensor modified with MPA. A novel SPR biosensor based on polydopamine-silver nanoparticles polydopamine-gold (PDA-Ag NPs-PDA-Au) membrane was constructed by layer-by-layer self-assembly technique and used to detect horse IgG. First, a layer of PDA film was assembled on the gold film, then Ag NO3 was reduced by PDA in situ to form a silver nanoparticles (Ag NPs), film, then a layer of PDA film was assembled. Finally, the antibody was connected to the PDA film by Schiff base reaction. The top PDA film can also effectively prevent Ag NPs from being oxidized. The morphology and thickness of the film were characterized by scanning electron microscope (SEM) and step meter (Talystep). The detection limit of the new SPR biosensor for horse IgG is 0.625 渭 g mL -1, which is 2 times lower than that of the PDA modified gold film biosensor and 4 times lower than that of the conventional MPA modified gold film biosensor. In addition, the new SPR biosensor has good stability and excellent reproducibility.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;TP212.3

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